"We don't discuss negotiations, but if it makes sense for both parties, we're open on both guys," Rizzo said.
In town for the Boston Baseball Writers' Association of America awards dinner, Rizzo said he's happy with his pitching staff, but didn't rule out adding an arm. Veteran starting pitchers Kyle Lohse and Javier Vazquez remain on the free-agent market.
The Nationals scouted Vazquez during winter ball in Puerto Rico, but the right-hander is undecided if he'll return to the Major Leagues for a 15th season after sitting out all of 2012.
"Only if it makes sense for us," Rizzo said of adding to his rotation competition. "We've got five terrific starters in the big leagues, we've got guys in the Minor Leagues for insurance and we've got prospects coming, so we're certainly in no need for another starter."
Evan Drellich is a reporter for MLB.com. Follow him on Twitter @EvanDrellich. This story was not subject to the approval of Major League Baseball or its clubs.